1. Field of the Invention
The present invention is generally directed to a welder system, and more particularly, to a welder system for welding fluid torque converters with precision.
2. Description of the Prior Art
Many types of welder systems are known in the art. One of these systems uses hydraulic or pneumatic cylinders to place the converter in the proper position for welding. Such a system is illustrated in FIGS. 1 and 2.
Fluid torque converters, an example of which is illustrated in FIG. 7, have an exterior housing of an engine side cover 100 and a bowl shaped primary pump driven side cover 102, which are welded together along their joining surfaces. These outer covers, along with the internal parts such as races and bearings 104, stator 105, and internal turbine 106, form the converter.
Before the engine side cover and the primary pump driven side cover can be properly welded, they must first be brought together and then an internal spacing must be made so that the internal parts operate properly.
In order to accomplish this, the unwelded covers, with the internal parts in place, are held in welder system 10 between a moveable faceplate 12 and a fixed chuck 14 as shown in FIG. 1. Primary pump driven side cover is clamped into fixed chuck 14 and moveable faceplate 12 is moved towards fixed chuck 14 until the converter is secured therebetween. Moveable faceplate 12 is moved into position by pressure cylinder 16 advancing shaft 15. Once moveable faceplate 12 and fixed chuck 14 holds the converter covers together, a spacer rod 28 passes through a hole in fixed chuck 14 and is inserted into the converter through the converter's primary pump drive tube. Spacer rod 28 advances into the converter in the direction of moveable faceplate 12 until it comes in contact with the internally disposed turbine. Cylinder 18 uses pressure to advance one end of spacer rod 28 until it makes contact with the internal turbine. The pressure applied to cylinder 18 is equal to the pressure applied to cylinder 16, so that moveable faceplate 12 stays in the same position.
After contact is made with the internally disposed turbine, a specific distance that the two discs are to be separated is manually calibrated. This is accomplished by manually adjusting adjusting nut 26 attached to the other end of spacer rod 28, which end is on the other side of cylinder 18. As a result of tolerance variations from one converter assembly to the next, adjusting nut 26 must be tightened against cylinder 18 and then loosened an amount equal to the specific precise distance for spacing of the internal parts required for the best possible operation. Due to the tolerance variations, this calibration must be made for each individual converter assembly.
Once this calibration is finished, spacer rod 28, controlled again by pressure cylinder 18, advances the turbine the specific distance by momentarily dropping the pressure on cylinder 16. This, in turn, allows cylinder 18 to push the inside face of the engine side cover to ensure the proper spacing of the internal parts and securely hold the engine side cover against the moveable faceplate without bolting before welding takes place.
One of the major problems with this welder system is the use of only one cylinder 18 to control the two separate movements of the spacer rod 28. The use of only one cylinder 18, along with the one cylinder 16 that controls the movement of the moveable faceplate 12, makes the system very susceptible to variations in pressure. For example, a drop in pressure in a cylinder, due to a drop in pressure in the pressure supply line, can cause the spacer rod 28, the moveable faceplate 12, or both, to move, thus altering the specific distance established and resulting in a lack of precision. These variations in pressure can easily occur when many devices use the same pressure supply line. Specifically, unwanted movement of the spacer rod 28, which results in an inaccurate internal spacing of the internal parts, can be caused by a change in the supply pressure.
Also, for accurate welding, the moveable faceplate 12 and fixed chuck 14 must be truly concentric, perpendicular to the axis connecting the centers of the fixed chuck 14 and moveable faceplate 12, and parallel in all planes. However, the welder system of the prior art is welded to a single metal block. This form of mounting makes it very difficult to adjust the welder system on all planes. Inaccuracies are thus created because a proper alignment does not exist.